Smart DNS™

Smart DNS™
  • Step 1 - Personal Computer queries the DNS server at the ISP asking what is the IP address for www.fatpipeinc.com.
  • Step 2 - The DNS at the ISP has never looked up www.fatpipeinc.com before, so there is no cached record for www.fatpipeinc.com. The DNS server at the ISP queries the Root name server asking what are the names and IP addresses of the Authoritative DNS servers for www.fatpipeinc.com.
  • Step 3 - The Root name server returns the IP addresses of the outside interfaces of the WARP (50.0.0.2, 100.0.0.2, 200.0.0.2) Since the FatPipe Unit acts as the Authoritative DNS server for www.fatpipeinc.com
  • Step 4 - The DNS at the ISP then queries the FatPipe Unit and asks for the IP address of www.fatpipeinc.com
  • Step 5 - The FatPipe Unit is constantly checking the health of its connections to the Internet, and only returns one of the available IP addresses for www.fatpipeinc.com to the ISP DNS server. That DNS record for www.fatpipeinc.com is then cached at the ISP DNS server for 10 seconds. The amount of time a DNS record is cached on a DNS server is controlled by the Authoritative DNS server (FatPipe Unit). This is called a TTL or Time To Live. Because the TTL is so short, everytime someone tries to go to www. fatpipe.com the FatPipe Unit will be queried. The FatPipe Unit will only dish out the IP address for www.fatpipeinc.com that it knows is available. If a line goes down then FatPipe Unit will no longer dish out the IP address associated with that line.
  • Step 6 - The ISP DNS server returns the IP address of www.fatpipeinc.com to the Personal Computer.

FatPipeĀ® Networks is well known for its patented and patent pending technology that provides redundancy, high reliability, and aggregate speed of WAN connections. Its core innovation for intelligent inbound load balancing and line failover is called SmartDNS. SmartDNS balances incoming IP traffic load and provides redundancy by allowing the host on the LAN to be accessible through multiple connections. SmartDNS supports the hosting of internal servers including web, e-mail, firewall and load balancing servers.

Basic Functionality of FatPipe's SmartDNS
  • Load Balancing: SmartDNS balances load by allowing the host on the network to be accessible through multiple connections. The host appears to be a different IP address at different times, thus using all available lines. The IP addresses are resolved based on the selected load-balancing algorithm.
  • Speed: Through load balancing, FatPipe's SmartDNS speeds up the delivery of inbound traffic.
  • Failover: FatPipe's SmartDNS will intelligently sense when a failure occurs and will make adjustments to the DNS replies so it will not resolve host names to the IP addresses that are associated with the connection that is down or unavailable.

FatPipe's SmartDNS allows hosts on a network to have multiple IP addresses associated with them from different providers, and will hand out the IP addresses for these hosts using the load-balancing algorithm selected by administrators. There are two FatPipe load-balancing algorithms: Round Robin and On Failure.

Round Robin sends IP packets sequentially over each connection to the Internet. This method is recommended for similar speed connections to the Internet, even if the connections are not the same kind (i.e.: combining two or three same speed Fractional T1s and a DSL line).

On-Failure balances a network's load based on the primary line's current availability. All traffic will be directed to the primary line(s). In case the primary line fails, all traffic will then be directed over the backup lines. Choose this option when combining a primary and a standby communications line.

SmartDNS Basic Setup Steps
Smart DNS™

Registering a New Domain

You must contact a domain registrar to register a domain name. In the course of registering the new domain, you may be required to provide two name servers that will handle your domain name. If the registrar provides default name servers, you can use them, otherwise just specify any existing domain name servers (perhaps just put in ns.yahoo.com and ns1.yahoo.com and their corresponding IP addresses). You will transfer these domains to your domain name server names in a future step anyhow.

Registering Name Servers

Contact your registrar to initiate the creation of your new name servers using your domain name (e.g. ns0.yourdomain.com and ns1.yourdomain.com). Each name server domain name will map to its own WAN port IP address on the FatPipe unit. So as far as the registrar knows, your domain name is handled on multiple physical name servers, but in reality you're simply mapping a different name server domain name to each of the WAN port IP addresses.

Setting Up DNS Zone (Domain Information) on FatPipe

To achieve inbound redundancy, each domain name record (e.g. www) will have multiple IP addresses assigned to it -- one from each WAN IP block. SmartDNS will hand out these IP addresses based on the type of load balancing you have set the FatPipe unit to use (Round Robin, On-Failure). See Figure 2.

A Basic Example

  • 1st WAN IP Block 11.11.11.0 - 11.11.11.255
  • 2nd WAN IP Block 12.12.12.0 - 12.12.12.255
  • 3rd WAN IP Block 13.13.13.0 - 13.13.13.255

IP Addresses on FatPipe WAN Ports

  • Port 2 (WAN) 11.11.11.2
  • Port 3 (WAN) 12.12.12.2
  • Port 4 (WAN) 13.13.13.2

SmartDNS Name Server Entries

  • ns0.yourdomain.com 11.11.11.2
  • ns1.yourdomain.com 12.12.12.2
  • ns2.yourdomain.com 13.13.13.2

SmartDNS Host Name Entries

  • www 11.11.11.5
  • www 12.12.12.9
  • www 13.13.13.44
  • ftp 11.11.11.7
  • ftp 12.12.12.35
  • ftp 13.13.13.19

Transferring the Domain to Your New Name Servers

Contact your existing registrar to initiate the transfer to your new name server domain names. This is usually done online by logging into your account at the registrar's website and filling out the proper request for transfer.

A Quick Note About Time to Live (TTL)

SmartDNS uses a short TTL to ensure the information about the IP addresses for the hosts it serves are accurate and up-to-date. This means that the machines on the Internet will always connect to the host using a route that is open instead of trying to access the host using an IP address that is not accessible due to a line failure.

The TTL value informs all DNS servers on the Internet how long they should store information about your domain. For example, a name server caches your domain information following a request for a website that uses your domain. Until the TTL value is exceeded, that name server will continue using the information supplied by the first request each time your domain is requested. When your domain is requested after the TTL period, the name server will conduct a new query for updated information about your domain. The TTL value is measured in seconds.

FatPipe uses a short TTL to ensure that DNS information is up-to-date. Administrators can change the TTL to their own preferences, along with Refresh, Expire and Retry settings.

Smart DNS™

Example

Figure 1 Explains the route of a DNS query while using FatPipe's SmartDNS. FatPipe unit features SmartDNS as part of its functionality, as does FatPipe MPVPN and MPFR. Please read below for a step-by-step explanation of the DNS process while using SmartDNS.

Step 1 Personal Computer queries the DNS at the ISP to get the IP address for www.fatpipeinc.com

Step 2 The DNS at the ISP has never looked up www.fatpipeinc.com before, so there is no cached record for www.fatpipeinc.com. The DNS server at the ISP queries the Root name server asking what are the IP addresses of the Authoritative DNS servers for www.fatpipeinc.com

Step 3 The Root name server returns the IP addresses of the outside interfaces of the FatPipe unit (50.0.0.2,100.0.0.2, 200.0.0.2) The FatPipe unit acts as the Authoritative DNS for www.fatpipeinc.com

Step 4 The DNS at the ISP then queries the FatPipe unit and asks for the IP address of www.fatpipeinc.com

Step 5 The FatPipe unit is constantly checking the health of its connections to the Internet and returns one of the IP address for www.fatpipeinc.com to the ISP DNS that FatPipe unit knows is working. That DNS record for www.fatpipeinc.com is then cached at the ISP DNS for 3 to 6 seconds. The amount of time a DNS record is cached on a DNS server is controlled by the Authoritative DNS (FatPipe unit).This is called a TTL or time to live. Every time someone tries to get to www.fatpipeinc.com the FatPipe unit will be queried because the TTL is so short. The FatPipe unit will only dish out the IP addresses for www.fatpipeinc.com that it knows are up. If a line goes down then FatPipe unit will no longer dish out the IP address associated with that line.

Step 6 The ISP DNS returns the IP address of www.fatpipeinc.com to the Personal Computer.

Step 7 The Personal Computer then connects to www.fatpipeinc.com using the newly acquired IP.

Conclusion

SmartDNS provides intelligent load balancing capabilities, redundancy and speed for IP traffic effectively without the need for BGP programming or any specialized knowledge of routing protocol or languages. SmartDNS does all the work for you, so you can get back to your other duties, and still be confident that your WAN will stay up and running despite intermittent failures in your network. For more information about FatPipe technology, products and services, please visit contact us at sales@fatpipeinc.com